When operating a retail store or other establishment that offers products for sale, it is important to regularly restock merchandise being displayed on the shelves, end caps and organized displays. Ideally, restocking is effected before or immediately upon exhaustion of the product being displayed. Since product turnover equates to profit in most retail establishments, the ability to constantly monitor on-shelf inventory, product availability and data indicative of sales or even theft can be important. It is further desirable that such systems include the ability to alert the retail store management and employees with regard to out of stock situations, low inventory or even unusual activity, to allow for corrective action as soon as possible. The ability to monitor sales activities on the basis of day of the week and time of day is recognized as an important capability allowing for enhanced sales activities.